This invention relates generally to a latch for releasably securing a first member relative to a second member. The first member moves at least partially relative to the second member resulting in a secured position.
Latches are used to releasably secure panels, covers, doors, drawers, electronic modules, glove boxes, and the like to other generally larger structures, such as housings, compartments, doorframes, panel fronts, frames, racks and other structures. These latches are mounted by various means, including screws, rivets, blade fasteners, spring clips, stake fasteners and other structures. Each latch generally includes a housing portion; and includes another portion, such as a lever, pull, button, stud, catch plate or other such structural member. The housing portion performs the function of the second, non-moving member, while the other portion performs the function of the first, moving member. Each latch is mounted so that the housing portion is fixed to the generally larger structure, i.e., the doorframe, panel front, frame, rack, and other structure.
When latches are used hold electronic and power modules and circuit breakers in power and distribution panels, or in communications panels, the operation of the latch and its ability to be installed and/or removed without tools or with unsophisticated tools becomes important. Moreover, it becomes desirable that the latch has a flush outer appearance or is nearly flush with the panel face when closed. These features are also desirable when latches are used to secure and to pull-out electronic module drawers, or power module drawers, in respective communications panels or power distribution panels, such as those found in communications and power distribution centers and/or substations and transmission nodes.
Often the conventional method for mounting electronics and /or opto-electronic modules in enclosures, i.e., housings and panels includes a printed circuit board mounted to a metal face plate (panel), or a metal drawer or tray which carries modules. In the past, these modules commonly were slid into an enclosure guided by card guides, ball slides, or some other form of linear guide. In each situation, there is an electrical connector on the back of the printed circuit board or tray which engages a mating (complementary) connector mounted inside the enclosure (the enclosure back plane).
There have been various designs for latches and connectors which either include spring biasing or deformable members for quick mounting. Atkinson, U.S. Pat. No. 2,720,772, shows a bag or suitcase latch with a pop-up movement. Aylott, U.S. Pat. No. 3,896,698, shows a quick release fastener, which has button activation and spring biasing. Vogel, U.S. Pat. No. 3,957,225, shows a tape cartridge latching mechanism with a spring biased release. Mahan, et al., U.S. Pat. No. 4,379,579, show a locking and ejecting hook assembly in which a releasable latch includes a spring and cam operated ejection. Nardella, et al., U.S. Pat. No. 4,618,118, show a molded latch housing with a flanged surface installed in a rectangular cutout. A spring connected the hook at the forward end of the latch keeps the latch normally in the locked position. Shimamura, et al., U.S. Pat. No. 4,724,310, shows a spring biased integrated circuit card drawer and carrier. Rudoy, U.S. Pat. No. 4,973,255, shows torque-type locking and ejecting mechanism for a PC cable connector. Rogers, et al., U.S. Pat. No. 5,048,877, show an automobile pop-up hood latch with a cable release and a spring biased open position. Kameyama, U.S. Pat. No. 5,279,509, shows a cable connector with deformable side stakes which act as a quick engagement mount. Once in the mounted position the stakes return to their original position to lock the mounting. Kohl et al., U.S. Pat. No. 5,575,163, show a removable attachment structure for a car radio, including a deformable spring lock member. Ellis, U.S. Pat. No. 5,620,213, shows a low profile pull-type latch used as a window lock. Wytcherley, et al., U.S. Pat. No. 6,203,076, show a fold down handle for a panel with controlled pushing and pulling action. Kuroda et al., U.S. Pat. No. 6,280,206, show a high voltage cable connector with deformable socket contacts which act as a locking mechanism once the two members of the connector are joined.
Previous latches have presented problems that make them difficult or impractical to use to mount and hold removable electronic modules or communications/ power distribution drawers. Specifically, these latches do not provide an adequate user (operator) finger grasping surface to pull open. The force necessary to open these latches and thereby disengage an electrical connector is substantial enough to cause discomfort to the fingers, when a user attempted to release the latch, i.e., to open the pull member. Furthermore, the prior electronic module latches do not consider electromagnetic interference, nor do they consider shielding against such interference, nor did they provide sufficient restraint during a physical shock.
It is desirable to provide a latch, which is capable of injecting an attached structure and ejecting that attached structure with user ease, and in retaining the structure secured from jarring loose during a shock or a seismic event.
It is also desirable to provide a latch, which can be used to secure a circuit board drawer in a communications center panel or a power distribution center panel face of an enclosure within the close tolerances found.
It is further desirable to provide a latch with a flush or nearly flush face.
It is even further desirable to provide a latch with a narrow footprint and low profile, with a quick mount and quick remove features without the need for specific tools.
It is additionally desirable to provide a latch with electromagnetic interference (EMI) shielding, and grounding to prevent electrostatic discharge (ESD) through the latch.
It is additionally desirable to provide a latch with an easy open feature.